大跨径钢桁架双层拱桥模态阻尼比分析方法  

Large-span Steel Truss Double-layer Arch Bridge Modal Damping Ratio Analysis Method

作　　者：贾延安 钱申春 郭瑞 王兵见[2] JIA Yanan;QIAN Shenchun;GUO Rui;WANG Bingjian(Anhui Highway and Bridge Engineering Co.,Ltd,Hefei 230031,China;Research Institute of Highway Ministry of Transportation,Beijing 100088,China)

机构地区：[1]安徽省公路桥梁工程有限公司,合肥230031 [2]交通运输部公路科学研究院,北京100088

出　　处：《交通与运输》2024年第1期27-31,共5页Traffic & Transportation

摘　　要：为有效揭示结构整体刚度的变化,解决当前模态阻尼识别准确性方面存在的突出问题,特别是在运营中的复杂桥梁结构,难以准确分离多种干扰因素,创新研究了复杂桥梁的模态阻尼比识别方法,只需有限数量的加速度传感器,即可精确且高效地分析复杂桥梁的模态阻尼比。首先,采用变分模态解耦方法,将实测的非线性振动信号准确分解为单一频率模式;其次,对这些分解后的信号应用希尔伯特变换和脉冲响应函数进行处理,从而建立模态阻尼比的求解策略;然后,选取服役中的公轨同层大跨径钢桁架双层拱桥作为实证研究对象,收集其主梁的加速度响应信号;再次,通过变分模态解耦与脉冲响应函数方法,成功分析信号特性,获取该结构的频率及阻尼比;最后,将这些频率数据与有限元模型分析结果进行比对,证实方法的准确性和可靠性。To effectively uncover overall stiffness changes in structures and address challenges related to accurately identifying modal damping,particularly in complex bridge operations,this study presents an innovative method for determining the modal damping ratio of complex bridges.This approach enables precise and efficient analysis using a limited number of acceleration sensors.Initially,the variational mode decomposition method is utilized to accurately separate measured nonlinear vibration signals into single-frequency modes.Subsequently,these decomposed signals are processed using Hilbert transform and impulse response functions to establish a method for determining the modal damping ratio.An in-service double-layer steel truss arch bridge with extended track-sharing layers is chosen as the empirical research subject,and the acceleration response signals from its main beam are collected.Through the application of variational mode decomposition and impulse response function methods,the signal characteristics are effectively analyzed,leading to the determination of the structure's frequencies and damping ratios.A comparison of these frequency data with results from finite element model analysis validates the accuracy and reliability of the proposed method.

关 键 词：阻尼比 钢桁架拱桥 信号分析 变分模态解耦 脉冲响应函数 

分 类 号：U491[交通运输工程—交通运输规划与管理]